This application describes a novel and innovative program of research designed to examine the therapeutic applications of virtual reality (VR) technology to solve the problem of generalizability of social skills training (SST) for children with higher functioning autism (HFA). Several studies indicate that SST has the potential to significantly improve the adaptive behaviors and quality of life of HFA children. However, cost and safety issues have prevented SST intervention paradigms from including effective methods to practice and generalize social skills beyond the immediate contexts of intervention. Therefore, the problem of generalizability currently impedes progress on the development of optimally effective SST programs for HFA children. One potential means for addressing this problem is to apply advances in VR technology to provide social skills practice environments for HFA children. VR environments may provide HFA children with varied but more controlled and safer social contexts, than are available in "real life", to practice social skills exercises that maximize learning while minimizing risks of failure and negative reinforcement learning ((McGeorge et al. 2001;Parsons et al. 2006;Standen &Brown, 2005). Therefore, a major aim of the R21 phase of this application is to bring together expertise in the study of virtual social interactions with expertise in the clinical science of autism to develop VR social skills practice tasks that may be used to augment current SST intervention methods for HFA children. A goal of the R33 phase is to provide an initial randomized case control test of the effectiveness of VR augmentation of SST with 42 HFA children between the ages of 8 and 18. The R33 phase of research will also be designed to provide empirical tests of novel hypotheses about measures of executive self monitoring and motivation associated with behavioral activation t may predict individual differences in responsiveness of HFA to treatment (Mundy et al. 2007). It is anticipated that the results of this program of research will support the development of a larger randomized controlled efficacy study of VR augmented SST for HFA children. The results will also support larger theory based examinations of the factors that affect individual differences in intervention responsiveness in autism. In addition, although the initial therapeutic focus of this research will be on SST for HFA children it is reasonable to expect that the general principles, procedures and VR intervention platforms developed in the course of this research will have the potential for widespread, cost-effective applications to interventions for a variety of other neuro- developmental disorders (e.g. ADHD) across a range of context (i.e. home, clinics and schools).